How many kWh can they squeeze into the Model 3...?

[JeffK]

You're correct, I shouldn't have said "moving parts." But fewer parts (layers) that are required with Cathode/Anode style batteries.

I don't know that they'll ever be economically or physically viable. They typically have lower energy densities and with electrolyte, weigh a lot more.

 

[Model 3]

he was referring to power so watt-hour is not a good correction

He was using the measurement of power, but should use the measurement of energy - as you correctly corrected him. And the measurement of power - that he used - is "watt" (or joules as @jja mentioned). The correspondent measurement of energy is "watt-hour". If you are talking about 1000'th of watt-hour it may be correct to add "k" (kilo = 1000) in front of this measurement of energy, but he was clearly talking about the last 1 watt not the last 1000 watt.

But anyway - no big deal. As I said, it was just a bit pedantic comment.

 

[Garlan Garner]

We have to call Tesla that they're doing it wrong!
Who can explain to me how the front motor in the D gets to do the most work?

Also, I was very much correct in stating that Tesla's motors are sized to take the last WATT from the battery pack. A Lego motor could take the last kWh out.
If you're going to be a smartypants, then get it right.

You never want to take the last watt from a LI battery. In much the same way you don't want to charge the LI battery in a Tesla to 100%.

Tesla has increased the possible range of its cars to 300 miles. Hardly anyone would ever be concerned with having to get the last KWH out of a battery.

 

[Red Sage]

People keep arguing as if it is the difference between a 4 cylinder ICE and a 12 cylinder. The difference between a Performance electric vehicle and a regular 'D' version is about the efficiency between a 6 cylinder and an 8 cylinder.

Hmmm... Actually, even closer... Like a 6 cylinder and a 6.5 cylinder, if such a thing existed. Apparently getting 'only' 91.84% of the range for improved 0-60 MPH runs is acceptable by Tesla Motors.

 

[Garlan Garner]

@ Garlan Garner
Take a breath. I'm not the enemy. And I believe in progress. Just, Tesla has as yet only show the 6% from 85 to 90kWh, over 4 year. The new cooling adds a bit of density to a pack perhaps, certainly per litre if not per kg. The 21-70 cells add density per liter (10%) and possibly a similar amount per kg.

Not EVERYTHING needs to be more efficient. I just wonder whether the motors Tesla uses to take the very last Watt from their battery packs are ideal for the often discussed range (and -anxiety).
Today's Tesla drivers are basically yups, right? Perhaps mid life crisis sufferers. Delivery drivers and pensioners are not yet part of the buying audience. Some will actually value (*gasp*) range over 0-60mph time. The D, while cruising at modest speeds in range mode sends most power to the smaller front motor. Seems small motors add range? And the power it can produce is still plenty for the average motorist. Also, big motors add cost.
This topic is about Model 3. The lowest cost car Tesla will ever offer. It's not only going to be the spare "wife" car for Model X and Roadster owners.
I don't think the big motors waste A LOT of range, but some, sure. And add cost. Competing EV's never seem to disappoint, as cars in general, for acceleration within road law.

The problem that I have is that you are too granular. Too specific.

The reason I say this is because people in this forum are not privy to all of the "REASONS" why Tesla does some things that they do.
Also, Tesla does not owe granular explanations to us "common folks". The only area where I believe Tesla owes any information is to their investors. The customers of Tesla have already raised their 400K M3 hands in approval.....let alone the 600K MS hands.

To be honest I want 0-60 short times over long range. 200 miles per charge was fantastic as it WAS. 300 miles per charge is icing on the cake. And I will say this....if 400 miles per charge shortens 0-60 even more.....I'm all in.
In other words..... All areas of the MS is more than good enough for me - even as it stands RIGHT NOW.
Elon and Tesla have obviously done a job "good enough" as far as its investors are concerned. Maybe not according to people in this forum.....but investors are more important - of which I am one.

 

[Garlan Garner]

Wrong.
One small motor outputting 20kW has more losses than one big motor outputting same 20kW.
Small motor has less/thinner wires, resulting in higher resistance and more losses.
Big motor has more/fatter wires with less resistance and hence less losses.

Basics.

I have to say that this is true. I have a project in the works right now at this very moment where I increased the wire size and drastically improved performance. I have converted my mower to all electric using LiFpo4 batteries and my cut time was 2 hours. I increased my wire diameter from 2 gauge to 0 and I increased my cut time by 25%.

 

[jbcarioca]

...

Wrong.
Bigger electric motor wastes LESS range than one smaller motor.

Basics, people, basics!

If you say "wrong" you need to get it right, and you did not bother to do so.

"other things remaining equal" a bigger motor wastes more energy than a smaller one simply because of more rotating mass. However other things are rarely equal, so many of the potential issues are not ones in reality. The Tesla motors on the front are optimized differently than are those in the rear. We may be confident that the net energy consumption of the smaller motors is lower than that of the larger ones. Were that not so Tesla would use different cruising logic, would they not?

I do not wish to be rude, but I find absolute statements are usually incorrect. Physics certainly warns us that things are relative...

 

[Garlan Garner]

If you say "wrong" you need to get it right, and you did not bother to do so.

"other things remaining equal" a bigger motor wastes more energy than a smaller one simply because of more rotating mass. However other things are rarely equal, so many of the potential issues are not ones in reality. The Tesla motors on the front are optimized differently than are those in the rear. We may be confident that the net energy consumption of the smaller motors is lower than that of the larger ones. Were that not so Tesla would use different cruising logic, would they not?

I do not wish to be rude, but I find absolute statements are usually incorrect. Physics certainly warns us that things are relative...

I really don't care what is more efficient or less efficient. I'm buying an M≡ with 2 motors and the largest battery they have. If they offer 3 motors..I'm getting that also.
Neither Tesla nor TMC offers "who knows the most" awards.

We won't get an chance to select "which motor" we get. So lets let it go.

 

[diamond.g]

I think to clarify Cloxxki's position he was referring to a supposed 20kWh battery which would probably be paired with a 180 kW motor which isn't terrible but although the vehicle would be lighter the range would be too poor to be viable.

eh. That would be a duty cycle question, no?

 

[jbcarioca]

I really don't care what is more efficient or less efficient. I'm buying an M≡ with 2 motors and the largest battery they have. If they offer 3 motors..I'm getting that also.
Neither Tesla nor TMC offers "who knows the most" awards.

We won't get an chance to select "which motor" we get. So lets let it go.

Neither do I, really, and I am making the identical motor decision you are, together with the most battery they'll offer.

 

[Cloxxki]

None of you got me.

I was questioning why a long range car (say 100kWh+) just HAS to be mated with motors which are combined able to match the battery's maximum discharge rate.
Can't a motor setup be found that wastes less heat to cruise are 100-120kph? OK, cool, so the 100kWh pack CAN deliver 500kW or more to the motors now. But should the motors spec'd by default be able to match the battery discharge rate?
A 2-ton car surely has plenty with 200kW. Perhaps it would suffer more (waste heat) when being pressed to extract this 200kW or even 100kW for an extended period of time than the now popularized 500kW approach. I wouldn't know, and ask to learn.

I suppose it may come down to why motor layout and scale produces the least heat in the range of cruising power, say 15-35kW?

 

[diamond.g]

None of you got me.

I was questioning why a long range car (say 100kWh+) just HAS to be mated with motors which are combined able to match the battery's maximum discharge rate.
Can't a motor setup be found that wastes less heat to cruise are 100-120kph? OK, cool, so the 100kWh pack CAN deliver 500kW or more to the motors now. But should the motors spec'd by default be able to match the battery discharge rate?
A 2-ton car surely has plenty with 200kW. Perhaps it would suffer more (waste heat) when being pressed to extract this 200kW or even 100kW for an extended period of time than the now popularized 500kW approach. I wouldn't know, and ask to learn.

I suppose it may come down to why motor layout and scale produces the least heat in the range of cruising power, say 15-35kW?

It doesn't have to be. It is just that currently that is how Tesla is choosing to do it. We won't know if it is better until someone else does a 100kwh battery.

 

[WarpedOne]

If you say "wrong" you need to get it right, and you did not bother to do so.

"other things remaining equal" a bigger motor wastes more energy than a smaller one simply because of more rotating mass. However other things are rarely equal, so many of the potential issues are not ones in reality. The Tesla motors on the front are optimized differently than are those in the rear. We may be confident that the net energy consumption of the smaller motors is lower than that of the larger ones. Were that not so Tesla would use different cruising logic, would they not?

Bigger rotating mass is not more loss but more accumulation. All energy that is "stored " in rotation is later released while slowing down. No loss.

Where exactly tesla gained efficiency by introducing 'smaller' motor in front we just don't know. But it has nothing to do with size or max kW the motor can produce.

What I object to is naive thought that just buy offering a weaker motor, the car would be more efficient. This notion is pure ICE-thinking and completely wrong. And it gets repeated just to often.

Almost as often as misusing W and Wh.

 

[dsvick]

I have converted my mower to all electric using LiFpo4 batteries and my cut time was 2 hours. I increased my wire diameter from 2 gauge to 0 and I increased my cut time by 25%.

"Increased"? So now it takes you longer? That's not a good thing

 

[Cloxxki]

Did an ICE driver steal your girlfriend in highschool, or recently?
I didn't get the units wrong and I didn't outright state that every smaller motor by default is more efficient than a bigger oen. Try and presume good knowledge and intentions from people. If something's not right, you may well not have understood correctly (WRONG) and could just ask for confirmation/explanation or elaborate in a friendly manner.

Seems plausible that Tesla designed a front motor to have ideal properties for typical cruising speeds. At least, they call it a "high efficiency motor paired to a high performance rear" one. And rather than making a slow car, added it to the existing layout, to tick many boxes at the same time. Acceleration, AWD, more regen, and what not.
Do we even know whether the front motor stays engaged near top speed for the PxxD models? It may not have the gearing and/or rpm range.

Might the "front" motor suffice as the sole rear motor for Model 3? They promised 0-60mph under 6 seconds. Would it manage that in a car that's well under 2 tons?

 

[Red Sage]

None of you got me.

Not too likely that we will.

I was questioning why a long range car (say 100kWh+) just HAS to be mated with motors which are combined able to match the battery's maximum discharge rate.

Pretty sure the question has been asked and answered by Tesla Motors Engineers time and again. In order to build a compelling car that is not slow and that makes the proper impression... YES. Toyota can build a fully electric Camry. No need for Tesla to do it for them.

Can't a motor setup be found that wastes less heat to cruise are 100-120kph?

Sure it can, by gimping it.

OK, cool, so the 100kWh pack CAN deliver 500kW or more to the motors now. But should the motors spec'd by default be able to match the battery discharge rate?

Yes. In fact, the motors should be specified to handle 750 kW (1006 HP), or 1,000 kW (1,341 HP) if possible. That is feasible, affordable, reliable, and durable, etc. The batteries with appropriate capacity and voltage/amperage can come later to take full advantage of that potential output.

A 2-ton car surely has plenty with 200kW. Perhaps it would suffer more (waste heat) when being pressed to extract this 200kW or even 100kW for an extended period of time than the now popularized 500kW approach. I wouldn't know, and ask to learn.

We aren't talking about ICE vehicles here. The Toyota Camry XLE V6 weighs just under 3,500 lbs and has a 268 HP engine with 248 ft-lbs torque. According to Car and Driver that car is:

Proof that good enough sells.

"Pumping out a healthy 268 horsepower, the V-6 car can scoot to 60 mph in 5.8 seconds and through the quarter-mile in 14.3 seconds at 100 mph."

And, to your point, 268 HP just happens to correspond to 200 kW. By my best guess is that would not qualify as particularly 'compelling', or even competitive in comparison to cars such as AUDI A4 2.04T Quattro, BMW 340i, Cadillac ATS 2.0T AWD, Infiniti Q50 RED Sport, Jaguar XE, Lexus IS, and Mercedes-Benz C300. I expect the base Model ☰ to be on the quicker side of 'under six seconds' 0-to-60 MPH and over 300 HP, so better than 402 kW in rear wheel drive form. The kick in the pants one might get from instantaneous torque is cool... But having that last through semi-legal speeds is even better.

I suppose it may come down to why motor layout and scale produces the least heat in the range of cruising power, say 15-35kW?

Wait... Hunh? What?!?

 

[lklundin]

The kick in the pants one might get from instantaneous torque is cool.

Not only is it cool but for a BEV the high performance does not come at a severe cost in energy efficiency, when you are not actually using it. Unlike for an ICE. Try to look at the energy efficiency for ICE's that manage 0-60 in less than 3 seconds. Do it per seat for extra fun.

Apart from the fact that Tesla can learn a lot from optimizing their power electronics along with improving their battery capacity, it also makes for a lot of positive media attention when they break a new 0-60 record.

 

[Jayc]

Having frequented Toyota Hybrid forums for the past 5 years, I know that their inverters are not as efficient as they would like. Now one of the major advances they are expecting in the next generation of Hybrid Synergy Drive is the use of SiC semiconductors in the inverter electronics. Does that mean Tesla inverters can also benefit from more efficient inverters or is Tesla's inverter design already as efficient as can be?

If we are expecting similar improvements with Tesla, that could mean more kW gets translated to HP.

 

[Garlan Garner]

"Increased"? So now it takes you longer? That's not a good thing

My cutting time increased - that's NOT a bad thing.

What do you thing an increase in cutting time means? It would help if we used our brains and not just feelings.

 

[Cloxxki]

Most people do not need such a fast car, or even want that throttle response when they have an itch. In fact, I lost a close family member when the spous accidentally (or was it a car glitch?) backed up suddenly when walking between a car and a wall.
If people could get a slight discount and not have more than 200kW, I bet many would take that. Current hipster buyers want the performance of course, but when we see 150kW packs putting out 800kW...cool, but is that a car or a weapon.

It's a very valid point that the performance comes at a lower effficiency cut compared with ICE's and that's really cool.